Archive: April 2014

Mislabelled or Food Fraud

Raw mince sample

There is growing concern that widespread mislabelling of meats is occurring in the UK. In some cases it is difficult to determine whether deliberate deception has been attempted or adventitious contamination has arisen due to poor hygiene practices; in others the consumer is deliberately being misled. Recent reports by West Yorkshire councils, Leicester City Council and Which? have revealed the potential extent of the risk. West Yorkshire councils reported that a third of the foods they tested were mislabelled, with meat products being the most likely to be adulterated. Leicester Trading Standards found that half of the meat products (e.g. burgers, curries) they checked were mislabelled. In the Which? survey, 60 lamb curries and minced lamb kebabs from takeaways around London and Birmingham were tested and 24 were found to contain other meats such as chicken and beef. On the 17th of this month the Food Standards Agency reported that it would prioritise testing of lamb takeaway dishes across the country due to these surveys and its own findings.  Sampling will start at the beginning of May. The mislabelling of food can result in fines of up to £5,000. The question now for the Public Analysts performing the tests is the choice of PCR method to use, those based on detecting nuclear DNA or others that detect mitochondrial DNA. There are a number of PCR techniques available (e.g. RFLP, RAPD); the methods Bio-Check can offer are reagents suitable for performing PCR with the Agilent 2100 Bioanalyzer – found in several Public Analyst laboratories – and also on real-time thermocyclers; these methods have a detection limit of 0.1%. But are there any suitable proteomic approaches? ELISA methods can detect adulteration in raw products at a limit of detection of 0.1 to 0.5% depending on the species, whilst in cooked products there are methods capable of detecting at the 1% level and others at 0.1% even in products thermally processed under conditions exceeding 133C and 3 bar pressure.

Posted in Speciation

Trends in Multitoxin Analysis

myco6in1mycotoxinstestkit_10002983Risk assessments of common food products for the presence of mycotoxins must be regularly performed to identify which classes are currently of interest (e.g. aflatoxins, ergots, fumonisins, ochratoxins, tricothecenes, zearalenone) from a health, economic and legal perspective. Their prevalence continually varies depending on many factors including the region, cultivation practices of agricultural commodities, weather and storage conditions. Analysis is necessary to assess their impact on human and animal health (acute or chronic), which is dependent upon levels of mycotoxins present and their effects (e.g. synergistic or additive) when different types of toxins occur together. Whilst legislation and guidance limits seek to address acute and chronic effects, recent advances in analysis using HPLC and LC MS/MS – particularly by companies such as Waters Corp. – have increased the possibilities for simultaneous detection of mycotoxins. Another Waters company, Vicam Corp., has led the field in immunoaffinity column development for multi-toxin analysis with the widest range available (e.g. AflaOchra, AOZ, DON-NIV, T2-HT2). This combination of multitoxin immunoaffinity columns for sample preparation and improvements in detection technologies has permitted low level detection of two or more toxins from a single sample extract. With LC MS/MS, screening for the presence of 200 or more mycotoxins is possible, though in doing so at such low levels, detection is inevitably compromised. Therefore, a narrower screen of the major classes of mycotoxins is preferred using such columns as Vicam’s Myco6in1+ columns, which detect eight different types of toxins (aflatoxins, ochratoxin A, fumonisins, deoxynivalenol, zearalenone, nivalenol, T-2 and HT-2 toxins).

Posted in Mycotoxins